Are all of a person's sins and transgressions due to the devil's actions, or are some of them due to the evil of the self, with no involvement from the devil?

Sins and transgressions have causes, including the self (nafs) and Satan. The self is prone to evil, and it is the vehicle of Satan and his entry point to man, except for those on whom their Lord has mercy. The chaining of devils may not necessarily prevent evil and disobedience, due to the existence of other causes such as wicked souls, bad habits, and human devils. A Muslim must fear Allah and beware of sins, whatever their cause, and be extremely cautious of Satan, who is a sworn enemy striving to lead man astray.